This application is based on applications Nos. 2000-211342 and 2000-214245 filed in Japan, the contents of which are hereby incorporated by reference.
1. Field of the Invention
The present invention relates to a projector having an outwardly extending duct and a duct for carrying a cooling air flow.
2. Description of the Background Art
Projectors are not only placed on a desk when in use but also used in various forms, for example, a pendent form in which a projector is mounted on or suspended from the ceiling of a room, a stacked form in which a plurality of projectors are vertically stacked one upon another, and a rear-projection form in which a projector is placed in a box-shaped enclosure.
However, the above-mentioned variations in usage form of the projector lead to variations in outside air intake condition at an air inlet of the projector. Depending on usage forms, the air inlet does not always satisfy a proper air intake condition, which might result in lower efficiency of cooling of the interior of the projector by a cooling fan.
On the other hand, a projector uses a duct for directing outside air (a cooling air flow) external to the projector thereinto to cool heat sources such as a liquid crystal panel and a light source lamp which are provided in the projector.
The projector contains heat-sensitive components such as an electronic circuit and an optical component.
Unfortunately, since the duct of the above-mentioned projector is made of plastic or the like and has constant thermal conductivity, placing the duct near the heat source such as the light source lamp causes the cooling air flow to be influenced by the heat source, resulting in the temperature rise of the cooling air flow. To prevent this, there arises a design constraint that the duct must be placed in isolation from the heat source.
Further, when placed near the heat source, the heat-sensitive component such as the electronic circuit is affected by heat radiation from the heat source. To prevent this, there arises a design constraint that the heat-sensitive component must be placed in isolation from the heat source.
The present invention is intended for a projector.
According to the present invention, the projector comprises: a projection section including an optical element for projecting an optical image onto a predetermined image surface; a housing for housing the projection section therein and having at least one opening, the housing being hollow; a duct disposed to extend from the opening to the outside of the housing, the duct having a connecting end for connection to the opening and an open end open to the outside of the housing; and an air flow generator for generating an intake air flow directed from the outside of the housing through the opening of the housing to a predetermined to-be-cooled portion of the projection section in the housing, the predetermined to-be-cooled portion being a heat-generating optical element, wherein the duct is movable to make the position and/or opening direction of the open end variable. Therefore, the projector is capable of drawing in the outside air from an outside position or direction in which the outside air suitable for cooling is obtained, thereby to efficiently cool the interior of the projector.
According to another aspect of the present invention, the projector comprises: a projection section including an optical element for projecting an optical image onto a predetermined image surface; a housing for housing the projection section therein and having at least one opening, the housing being hollow; a duct disposed to extend from the opening to a predetermined to-be-cooled portion of the projection section, the predetermined to-be-cooled portion being a heat-generating optical element, at least part of the duct being made of a thermal insulation material; and an air flow generator for generating an intake air flow directed from the outside of the housing through the opening of the housing via the duct to the predetermined to-be-cooled portion in the housing. Therefore, the projector is capable of shutting off heat radiation from a heat source, thereby to contribute to an improvement in design flexibility of the projector.
It is therefore an object of the present invention to provide a projector capable of efficiently cooling the interior thereof.
It is another object of the present invention to provide a projector with improved design flexibility.
These and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description of the present invention when taken in conjunction with the accompanying drawings.